DE69831255T2 - METHOD AND DEVICE FOR TRANSFERRING DATA IN A MULTI-TRANSMISSION SYSTEM - Google Patents

Description

background the invention

I. area the invention

The The present invention relates to a method and an apparatus for transmission of data in a multi-carrier system. The present invention can be used to maximize system throughput and to enlarge the signal diversity be used, by dynamic multiplexing of the signals on multiple carrier in a spread spectrum message system.

II. Description of related technology

It is desired to be able to transmit data at rates that are higher as the maximum data rate of a single CDMA channel. A traditional one CDMA channel (as for the cell message transfer standardized or standardized in the United States) capable of digital data at a maximum rate of 9.6 bits to transfer per second using a 64-bit Walsh spreading function 1.2288 MHz.

Lots solutions This problem has been suggested. One solution is to assign multiple channels to users and to allow these users to share data in parallel on a variety of channels, available to you are, send and receive.

Two A method of providing multiple CDMA channels for use by a single users are in pending US patents 6,005,855 entitled "METHOD AND APPARATUS FOR PROVIDING VARIABLE RATE DATA IN A COMMUNICATIONS SYSTEM USING STATISTICAL MULTIPLEXING "and US Patent 5,777,990 entitled" METHOD AND APPARATUS FOR PROVIDING VARIABLE RATE DATA IN A COMMUNICATION SYSTEM USING NON-ORTHOGONAL OVERFLOW CHANNELS "described, the two patents being assigned to the assignee of the present invention are.

moreover can frequency diversity can be obtained by transmitting data over multiple spread spectrum channels, the separated from each other in terms of frequency are. A method and apparatus for redundant transmission of data over Multiple CDMA channels is described in U.S. Patent 5,166,951, entitled "HIGH CAPACITY SPREAD SPECTRUM CHANNEL ". The use of Code Division Multiple Access (CDMA) modulation techniques is one of several techniques to facilitate communication or Telecommunications, being a big one Number of system users is present. Other multiple access communication system techniques such as time division multiple access (TDMA) multiple access) techniques, Frequency Division Multiple Access (FDMA) multiple access) techniques? and AM modulation schemes such as Amplitude extended or companded single sideband (ACSSB) techniques are known. The spread spectrum modulation technique of the CDMA has however, significant advantages over these other modulation techniques for multiple access communication systems.

The Use of CDMA techniques in a multiple access communication system is described in U.S. Patent 4,901,307 entitled "SPREAD SPECTRUM MULTIPLE ACCESS COMMUNICATION USING SATELLITE OR TERRESTRIAL REPEATERS. "The use of CMDA techniques in A multiple access communication system is further disclosed in the U.S. patent 5,103,459, entitled "SYSTEM AND METHOD FOR GENERATING SIGNAL WAVEFORMS IN CDMA CELLULAR TELEPHONE SYSTEM. "Both patents are to the owner of the present invention. CDMA or code division multiple access communication systems are in the United States Standardized according to the Telecommunications Industry Association Interim Standard IS-95 entitled "Mobile Station Base Station Compatibility Standard for Dual Mode Wideband Spread Spectrum Cellular System ".

The CDMA waveform, due to its inherent nature of being a wideband signal, offers a form of frequency diversity by spreading the signal energy over a wide bandwidth. Therefore, the frequency-selective fading affects only a small part of the CDMA signal bandwidth. Space or path diversity on the forward / reverse link is obtained by providing multiple signal paths through simultaneous connections to / from a mobile user over two or more antennas, cell sectors or cell sites. Further, path or path diversity can be obtained by exploiting the multipath environment by spread spectrum processing by allowing a signal arriving with different propagation delays is received and processed separately. Examples of the exploitation of path or web diversity are illustrated in the following US patents: No. 5,101,501 entitled "SOFT HANDOFF IN CDMA CELLULAR TELEPHONE SYSTEM" and No. 5,109,390 entitled "DIVERSITY RECEIVER IN A CDMA CELLULAR TELEPHONE SYSTEM ", both patents are assigned to the assignee of the present invention.

XP000639647 describes a Modified Multiple Carrier (MC) Direct Sequence Code Division Multiple Access (DS-CDMA) system for use over slow Multipath fading channels with frequency selectivity in the reverse link transmission a cellular network. Instead of transmitting data sub-streams uniformly across subchannels, jump the data substrates via subchannels with jump patterns, which are adaptively adjusted to the channel fading characteristics.

US Patent No. 5,410,538 describes a method for transmitting signals from a mobile unit to a base station using multiple tone techniques. A frequency band is divided into a plurality of generally evenly spaced ones Divided sound. The sounds are subdivided into a predetermined number of sentences, each one of them a predetermined number of tones contains. Each unit within a given sector becomes a phrase for transmission assigned by information signals. The sounds within each soundtrack are chosen that transmit the modulated signals through each unit are orthogonal with respect to all other sets of sentences, the units are assigned in this sector. Neighboring cells do not have more than one tone in common.

1 FIG. 12 illustrates a transmission or transmission scheme for a multicarrier code division multiple access (CDMA) system in which each carrier carries or transports a fixed fraction of the transmitted data. Variable rate frames of information bits are sent to the encoder (CONVOLUTIONAL ENCODER) 2 which encodes the bits according to a convolutional encoding format. The coded symbols are sent to symbol repetition means (SYMBOL REPETITION) 4 delivered. Symbolwiederholmittel 4 repeat the coded symbols to provide a fixed rate of symbols from the symbol repeats 4 regardless of the rate of information bits.

The repeated symbols are sent to a BLOCKINTERLEAVER or BLOCKVERSCHACHTELER 6 which rearranges or rearranges the sequence in which the symbols are to be transmitted or sent. The interleaving process coupled with the forward error correction provides time diversity which is helpful in the reception and error recovery of the transmitted signal in the case of "burst" errors. The interleaved or nested symbols are delivered to a data scrambler or data scrambler. The data scrambler multiplies each "interleaved" symbol by +1 or -1 according to a pseudonoise (PN) sequence. The pseudonoise sequence is provided by generating a long PN sequence by the long code generator (LONG CODE GENERATOR) 8th with the chip rate through the DEZIMATOR 10 which selectively provides a subset of the long code sequence chips at a rate of the interleaved symbol stream.

The data from the data scrambler is sent to the demultiplexer (DEMUX) 14 delivered. The demultiplexer 14 divides the data stream into three equal sub-streams. The first sub-stream is sent to the sending subsystem 15a delivered, the second sub-stream is sent to the transmission subsystem 15b delivered and the third sub-stream is sent to the transmission subsystem 15c delivered. The subframes are connected to serial-to-parallel converters (BINARY TO 4 LEVEL = BINARY TO 4 LEVEL) 16a - 16c delivered. The outputs of the serial-to-parallel converter 16a - 16c are quaternary symbols (2 bits / symbol) for transmission in a QPSK modulation format.

Signals from the serial-to-parallel converters 16a - 16c become Walsh coders 18a - 18c delivered. In the Walsh coders (WALSH CODING) 18a - 18c gets the signal from each of the converters or converters 16a - 16k multiplied by a Walsh sequence consisting of ± 1 values. The Walsh encoded data is sent to the QPSK spreader (QPSK SPREAD) 20a - 20c which spread the data according to two short PN sequences. The short PN sequence spread signals are sent to the amplifiers 22a - 22b supplied amplify the signals according to a gain factor.

Tabelle 1

sps

= Symbole pro Sekunde

The system described above suffers from a variety of disadvantages. First of all, note that since the data must be provided in equal sub-streams on each of the carriers, the available numerology is limited to frames having a number of code symbols which is to be equally divided by a factor of three. Table 1 below illustrates the limited number of possible rate sets that can be obtained using the 1 shown transmission system are available.

Table 1

sps

= Symbols per second

There, As shown in Table 1, the symbols are uniform the three carriers distributed, is the total data rate by the carrier with the lowest available Performance or the highest SNR requiring carrier limited. This means, the total data rate is equal to three times the data rate of the "worst" connection (here The word worst connection means the one that requires the highest SNR or the least available Has power). This reduces system throughput as the rate of Worst connection always than the common rate for all three carrier is chosen which underutilizes the channel resource among the two better ones Has connections.

Secondly Note the following: the frequency dependent fading can be more serious Way one of the frequencies affect while a limited effect occurs at the remaining frequencies. Third, be the following noticed: because of the frequency-dependent Fadings, fading is always typically the same groups of symbols of each frame. Fourth, be the following notes: where the implementation is superimposed on a voice transmission system or superimposed there is not a good way the loads carried on the different frequencies on a frame-by-frame basis in view of the variable language activities in each Frame balance. This results in a loss in overall system throughput. And fifth, be finally noticed that for a system with only three frequency channels with the described implementation There is no procedure for separating the language and the data so the data on a frequency or a set of frequencies, and the language on a different frequency or one Set of frequencies. This gives, as mentioned above, a Loss of system throughput.

It is therefore necessary to seek an improved multi-carrier CDMA message system offering greater flexibility in numerology and load balancing, and also better resolution at the data rates and finally provides superior performance despite the frequency-dependent fading and non-uniform loading.

Summary the invention

According to one Aspect, the invention provides a transmitter or transmitter, and though for a multi-carrier CDMA message or communication system for transmission of data at a data rate in a plurality of channels whose everyone has a capacity which is smaller than the data rate, the sender has the following comprising: a control device (controller) for determining the capacity each of the multitude of channels and selecting a data rate for depending on each channel of the specific capacity; a variable demultiplexer in response to the control device for demultiplexing the coded data into a plurality of transmission or transmission subsystems derived at a demultiplex rate selected from the data rates for the channels by the control device, wherein the plurality of transmission subsystems responds to the controller and each with a corresponding one the multitude of channels is associated with scrambling the coded data with codes unique to the channel for transmission are in the channel.

According to one Another aspect of the invention is a receiver for a multiple carrier CDMA message system provided, the receiver Comprising: a receiving circuit for receiving signals simultaneously in a variety of channels, each of the signals scrambled coded symbols defining together data from one common Represent origin; a controller (controller) for determining a symbol rate for the Signals in each channel; a variety of receiving subsystems appealing on the control device and each associated with a corresponding one the multitude of channels for descrambling (descrambling) the decoded symbols with codes, unique to the channel, to enable, that the data is extracted from it; and a variable multiplexer in response to the control device for multiplexing the data from the plurality of receive subsystems, at a multiplex rate derived from the symbol rates determined for the channels by the controller at one exit.

According to one Another aspect of the invention provides a wireless transmitter, comprising: an encoder for receiving a set of information bits and coding the information bits to provide a set of code symbols; and a transmission subsystem for reception the code symbols and to provide a subset of the code symbols on a first carrier frequency and the remaining symbols on at least one additional one Carrier frequency.

The The invention also provides a method for transmitting data in one A multi-carrier CDMA communication system having a data rate in a plurality of channels, each having a capacity, which is less than the data rate, the method has the following provides: determining the capacity each of the multitude of channels and selecting a data rate for depending on each channel of the specific capacity; Demultiplexing the encoded data in the plurality of channels a dumultilexrate derived from the data rates selected for the channels the control device; and scrambling the encoded data Codes that are unique to the channel for transmission in the channel.

The The invention further provides a method for receiving data in a multi-carrier CDMA messaging system, the method comprising: receiving signals simultaneously in a variety of channels, with each of the signals scrambling coded symbols defining together data from one common Represent origin; Determine a symbol rate for the signals in each channel; Descrambling or descrambling the encoded symbols in each channel with codes that are unique for the channel to enable that the data is extracted from it; and multiplexing the unscrambled or descrambled data from the plurality of channels at a multiplex rate derived from the symbol rates determined for the channels.

Around It is better to exploit the channel resource or the channel stock necessary to transmit a different data rate on each medium or to send according to the channel state and availability of power on each channel. One way to do that is to The relationship of inverse multiplexing on each of the carriers. Instead of distribution the symbols with a relationship from 1: 1: 1 can be a more arbitrary one relationship to be used together with different types of repetition or repetition schemes, as long as the result is Symbol rate on each vehicle Factor of some Walsh function rate is. The Walsh feature rate can be 1228800, 614400, 307200, ..., 75 for Walsh function length of 1 to 16384.

If for one given Walsh function length the symbol rate is lower than the Walsh function rate is uses the symbol repeat to match ("match") to the rate. The repetition factor can be any number, integer or fraction. The expert recognizes that if repetition exists, the total transmission power can be proportionally reduced to to keep the code symbol energy constant. The Walsh function length can on all three carriers be the same or not, depending on whether the code channels saved should be. For example, if the viable code symbol rate is set to three channels 153600 sps, 30720 sps, and 102400 sps (for rate 1/2 encoding, respectively) these data rates of 76.8 kbps, 15.36 kbps and 51.2 kbps, respectively - the overall data rate is 143.36 kbps), then the inverse multiplexing ratio is 15: 3: 10.

If a Walsh function of length 8 for all three channels is used (assuming QPSK modulation with a QPSK symbol rate of 153.6 Ksps), then each code symbol is transmitted twice or 10 times or three times on the three channels. Additional time diversity can be obtained when the repeated symbols are interleaved become. In an alternative embodiment, different Walsh function lengths used. For example, you can Walsh features for the three channels in the above example of length of 16 or 16 plus 8 are used, with each code symbol once on the first channel, five times on the second channel and three times on the third channel becomes.

The above possible solution does not affect the encoder because it has to be able to the highest Anyway to handle data rate. Everything that is changed is the number the octets of the data at the encoder input. This solution but has an impact on the implementation of the interleaver, because the interleaver many possible Sizes (in terms the number of symbols) when all combinations of data rates on the three channels permissible are. An alternative to the above solution that makes the problem more difficult is the inverse multiplexing of the code symbols from the encoder the three carriers directly and the implementation nesting or interleaving the repeated code symbols separate each channel. This simplifies numerology and reduces the number of possible On interleaver sizes every channel.

Short description the drawings

Further Features, objects and advantages of the invention will become apparent from the detailed description below with reference to exemplary embodiments the invention is given in connection with the drawings, where like numerals denote identical things; in the Drawing shows:

1 FIG. 4 is a block diagram illustrating a fixed rate and carrier multi-frequency CDMA message system; FIG.

2 a block diagram illustrating a transmission system embodying the present invention;

3 a block diagram illustrating a receiver system embodying the present invention; and

4 a table of code channel Walsh symbols in a traditional IS-95 CDMA communication or messaging system.

detailed Description of preferred embodiments

With reference to 2 Fig. 12 is a block diagram illustrating a transmission system embodying the present invention, wherein the first operation to be performed is that of determining the amount of data that can be accommodated on each of the carriers.

Three such carriers are in 2 Although those skilled in the art will appreciate, the present invention can be readily extended to any number of carriers. The control processor (CONTROL-PROCESSOR) 50 determines the data transmission rate on each of the carriers based on a set of factors such as the load on each of the carriers, the amount of data queued for transmission to the mobile station, and the priority of the information to be transmitted to the mobile station.

After the data rate to be sent is selected on each of the carriers, the control processor selects 50 a modulation format capable of transmitting the data at the selected rate. In the exemplary embodiment, Walsh sequences of different lengths are used to modulate the data, depending on the rate of data to be transmitted. The use of different length Walsh sequences selected to modulate the data depending on the rate of data to be transmitted is described in detail in US Patent 5,930,230 entitled "HIGH DATA RATE WIRELESS COMMUNICATION SYSTEM". and which is assigned to the assignee of the present invention. In an alternative embodiment, the high data rate can be achieved by bundling the CDMA channels, which is described in US Pat. No. 6,005,855 and US Pat. No. 5,777,990.

Once the rates possible on each of the carriers have been selected, the control processor calculates 50 an inverse multiplexing ratio that determines the size of each transmission performed on each of the carriers. For example, if the possible or supportable code symbol rate on each of the three carriers is 153,600 sps, 30,720 sps, or 102,400 sps (for rate 1/2 encoding, this translates to data rates of 76.8 kbps and 15.36 kbps, respectively) 51.2 kbps - the total data rate is 143.36 kbps) then the inverse multiplexing ratio will be 15: 3: 10.

In the exemplary embodiment, the information bits are sent to the frame formatter (FRAME FORMAT). 52 delivered. In the exemplary embodiment, the formatter generates 52 a set of cyclic redundancy check bits (CRC bits) and appends these to the frame. In addition, the formatter hangs 52 a predetermined set of tail bits. The implementation and construction of the frame formatters is well known in the art and an example of a typical frame formatter is described in U.S. Patent No. 5,600,754 entitled "METHOD AND SYSTEM FOR THE ARRANGEMENT OF VOCODER DATA FOR THE MASKING OF TRANSMISSION CHANNEL INDUCED ERRORS ", which patent is assigned to the assignee of the present invention.

The formatted data is sent to the encoder (ENCODER) 54 delivered. In the exemplary embodiment, the encoder is 54 a convolutional encoder, although the present invention could be extended to other forms of encoding. A signal from the control processor 50 shows the encoder 54 the number of bits to be coded in this transmission or transmission cycle. In the exemplary embodiment, the encoder is 54 a rate 1/4 convolutional encoder with a constraint length of 9. It should be understood that because of the additional flexibility provided by the present invention, essentially any encoding format may be used.

The coded symbols from the encoder 54 are available at the variable ratio demultiplexer (VAR.RATIO DEMUX) 56 delivered. The variable ratio demultiplexer 56 provides the coded symbols to a set of outputs based on a symbol output signal supplied by the control processor 50 , In the exemplary embodiment, there are three carrier frequencies and the control processor 50 provides a signal representing an indication of the number of coded symbols to each of the three outputs. Those skilled in the art will recognize that the present invention is readily extendible to any arbitrary number of frequencies.

The demultiplexers at each of the variable ratio outputs 56 supplied encoded signals are converted to corresponding symbol repetition means (SYMBOL REPRETITION) 58a - 58c delivered. The symbol repeats 58a - 58c generate repeated versions of the coded symbols such that the resulting symbol rate is matched to the carrier-based data rate, and in particular to the Walsh function rate used on that carrier. The implementation of the repeater generators 58a - 58c is known in the art and an example of which is described in detail in U.S. Patent 5,629,955 entitled Variable Response Filter. This patent is assigned to the assignee of the present invention. The control processor 50 provides a separate signal to each of the repeaters 58a - 58c , indicating the rate of symbols on each carrier or, alternatively, the size of the repetition to be provided on each carrier. In response to the signal from the control processor 50 generate repeating agents 58a - 58c the required numbers of repeated symbols to deliver the designated symbol rates. It should be noted that in the preferred embodiment, the size of the repeat is not limited to any integer where all symbols are repeated with the same number of times or times. A method of providing non-integer repetition is described in detail in US Pat. No. 6,480,521, entitled "METHOD AND APPARATUS FOR TRANSMITTING HIGH SPEED DATA IN A SPREAD SPECTRUM COMMUNICATION SYSTEM". This Pa tent is assigned to the assignee of the present invention.

The symbols of the repeaters 58a - 58c are sent to a corresponding one of the INTERLEAVER or permuter 60a - 60c delivered, the permuter 60a - 60c reordering the repeated symbols according to a predetermined permutation procedure. The control processor 50 provides a permutation format signal to each of the permuters 60a - 60c which indicates a format of a predetermined set of permutator or interleaver formats. In the exemplary embodiment, the permutation format is selected from a predetermined set of "bit-reversal" permutation formats.

The reordered symbols from the INTERLEAVERS 60a - 60c will be sent to data scramblers 62a - 62c delivered. Each of the data scramblers 62a - 62c changes the sign of the data according to a pseudonoise (PN) sequence. Each PN sequence is provided by passing a long PN code generated by a long or PN generator 82 with the chip rate through the decimator 84a - 84c which selectively provides spread symbols from the spread symbols by a PN sequence at a rate no higher than that by the PN generator 82 intended to provide. Since the symbol rate at each carrier may be different from each other, the decimation rate of the decimators may be 84a - 84c be different. The decimators 84a - 84c are sample and hold circuits containing the PN sequence from the PN generator 82 and continue to output this value for a predetermined period. The implementation of the PN generator 82 and the decimators 84a - 84c is known and described in detail in the above-mentioned US Pat. No. 5,103,459. data scrambler 62a - 62c subject the binary symbols to the interleavers 60a - 60c and the decimated pseudonoise binary sequences from the decimators 84a - 84c an exclusive OR processing.

The binary scrambled symbol sequences are supplied as standard to parallel converters (BINARY TO 4 LEVEL = BINARY TO 4-LEVEL) 64a - 64c delivered. Two binary symbols delivered to the converter 64a - 64c are plotted on a quaternary constellation with values (± 1, ± 1). The constellation values are sent to two outputs from converters 62a - 62c intended. The symbol streams from the converters 64a - 64c are separate for Walsh spreaders (WALSH CODING) 66a - 66c intended.

It There are many methods for providing high-speed data in a code division multiple access communication system. In the preferred embodiment the Walsh sequence length is varied namely according to the rate of the data to be modulated. Shorter Walsh sequences become used to a higher Speed-modulating data and longer Walsh sequences are used to modulate the lower data rate. For example can use a 64-bit Walsh sequence will transfer data at 19.2 Ksps. However, one can 32-bit Walsh sequence used to generate data at 38.4 ksps modulate.

A system describing Walsh Sequence Modulation with variable length is given in detail in US Pat. No. 6,173,007 entitled "HIGH DATA RATE SUPPLEMENTAL CHANNEL FOR CDMA TELECOMMUNICATIONS SYSTEM". The length of the Walsh sequences used to modulate the data depends on the rate of data to be sent. 4 illustrates the Walsh features in a traditional IS-95 CDMA system.

In the preferred embodiment of the invention, the number of Walsh channels assigned for the high rate data may be any value of 2 ^N , where N = {2, 3, 4, 5, 6}. Made by the Walsh coders 66a - 66c Walsh codes used are 64/2 ^N symbols long instead of the 64 symbols used with the IS-95 Walsh codes. Thus, the high data rate owning channel is orthogonal to the other code channels with 64-symbol Walsh codes, ^2N of the possible 64 Quaternary phase channels with 64-symbol Walsh codes eliminated from use. Table I provides a list of possible Walsh codes for each value of N and the corresponding sets of assigned 64-symbol Walsh codes.

Tabelle I.

Table I.

The + and - signs indicate a positive or negative integer value, with the preferred integer being 1. As is obvious, the number of Walsh symbols in each Walsh code varies as N varies or changes, and in all cases is less than the number of symbols in the IS-95 Walsh Ka nal codes. Regardless of the length of the Walsh code in the described embodiment, the symbols are applied at a rate of 1.2288 Megachips per second (Mcps). Thus, the shorter-length Walsh codes are repeated more often. The control processor 50 provides a signal to the Walsh coding elements 66a - 66c indicating the Walsh sequence to be used to spread the data.

alternative Method of transmission high rate data in a CDMA communication system also include methods commonly referred to as channel bundling techniques be designated. The present invention is the same on the channel bundling method to apply, to provide high-speed data in a CDMA communication system. A method for providing channel bundling Data is that a variety of Walsh channels for Use by a signal user is provided. This method is described in detail in U.S. Patent 5,818,871. An alternative Channel bonding technology is the user with the use of a Walsh code channel but to differentiate or differentiate the signals from each other by means of different scrambling or scrambling signals as described in detail in U.S. Patent 5,777,990.

The Walsh spread data is sent to the PN spreader 68a - 68c which apply a short PN sequence spread to the output signals. In the exemplary embodiment, the PN spreading is performed by means of a complex multiplication, as described in detail in US Pat. No. 6,793,907. Data channels D _I and D _Q are complex multiplied, as the first real or imaginary parts or expressions with spreading codes PN _I and PN _Q as second real or imaginary parts with the result of an in-phase (or Real) part X _I and a quadrature phase (or imaginary) part X _Q. The spreading codes PN _I and PN _Q are by spreading code generators 67 (PN _I ) and 69 (PN _Q ) generated. Spreading codes PN _I and PN _Q are at 1.2288 Mcps. Equation (1) illustrates the performed complex multiplication. (X I + jX Q ) = (D I + jD Q ) (PN I + jPN Q ) (1)

The in-phase term or term X _I is then low-pass filtered to a 1.2288 MHz bandwidth (not shown) and upconverted by multiplication with the in-phase carrier COS (ω _c t). Similarly, the quadrature phase term X _{Q is} low pass filtered to a 1.2288 MHz bandwidth (not shown) and upconverted by multiplication with the quadrature phase carrier SIN (ω _c t). The up-converted X _I and X _Q terms are summed to give a forward link signal s (t). The complex multiplication allows the quadrature-phase channel set to remain orthogonal to the in-phase channel set and therefore can be provided without adding additional interference to the other channels, and transmitted over the same path with perfect receiver phase recovery or recovery.

The PN spread data are then sent to the filters 70a - 70c which spectrally shape the signals for transmission. The filtered signals are applied to gain multipliers (GAIN) 72a - 72c which amplify the signals for each carrier. The gain factor is applied to the reinforcing elements 72a - 72c through the control processor 50 delivered. In the exemplary embodiment, the control processor selects 50 the amplification factor for each carrier according to the channel state and the rate of information data to be transmitted to that carrier. As is known to those skilled in the art, data transmitted with repetition or repetition may be transmitted with lower symbol energy than data without repetition.

The amplified signals are sent to an optional or optional switch (SWITCH) 74 delivered. The desk 74 provides additional flexibility of channeling the data signals to different carriers. Typically, the switch 74 only if the number of carriers actually used to transmit the signal is less than the total number of possible carriers (3 in the present example).

The data will be through the switch 74 to carrier modulators (CARRIER MODULATION) 76a - 76c delivered. Each of the carrier modulators 76a - 76c converts the data up to a different predetermined frequency. The up-converted signals are sent to the transmitter (TMTR) 78 where they are combined with other similarly processed signals, filtered and amplified for transmission by the antenna 80 , In the exemplary embodiment, the amplified frequency at which each of the signals is transmitted changes over time. This provides additional frequency diversity for the transmitted signals. For example, a signal that is currently or continuously passing through the Trä germodulator 76a is switched at predetermined time intervals so as to be at a different frequency by carrier modulators 76b or 76c to be transferred. According to a signal from the control processor 50 the switch initiates 74 an amplified input signal from the gain multiplier 72a - 72c to a corresponding carrier modulator 76a - 76c ,

Now be on 3 Reference is made to where a receiver system embodying the present invention is illustrated. That at the antenna 100 received signal becomes the receiver (RCVR) 102 which amplifies and filters the signal before switching it to the switch 104 supplies. The data is by switch 104 to a corresponding carrier demodulator 106a - 106c delivered. It will be appreciated by those skilled in the art that while the receiver structure is described for receiving a signal transmitted on three frequencies, the present invention may be readily transmitted to any number of frequencies that are consecutive or not.

When the carriers on which the data is transmitted are rotated or skipped to provide additional frequency diversity, the switch provides 104 the received signal to a selected carrier demodulator 106a - 106c in response to a control signal from the control processor 125 , If the carrier frequencies are not skipped or rotated, then the switch is 104 unnecessary. Each of the carrier demodulators 106a - 106c , which performs quaternary phase-shifting "keying" on QPSK (QPSK), demodulates the received signal to baseband using a different down-conversion frequency to provide separate I and Q baseband signals.

The downconverted signals from each of the carrier demodulators 106a - 106c are sent to a corresponding PN despreader (PN-DESPREAD) 108a - 108c which removes the short code spread from the downconverted data. The I and Q signals are despread by complex multiplication with a pair of short PN codes. The PN despreading data is sent to the Walsh demodulators 110a - 110c which reveals the data according to the assigned code channel sequences. In the exemplary embodiment, Walsh functions are used in the generation and reception of the. CDMA signals are used, but other forms of code channel generation are equally applicable. The control processor 125 sends a signal to the Walsh demodulators (WALSH DEMOD) 110a - 110c , indicating the Walsh sequences to be used to uncover the data.

The Walsh despread symbols are sent to parallel-to-serial converter (4-LEVEL TO BINARY = 4-LEVEL TO BINARY) 112a to 112c supplied, which apply the 2-dimensional signal in a 1-dimensional signal. The symbols are then sent to the descramblers (DE-SCRAMBLE) 114a - 114c delivered. The descramblers 114a - 114c descramble or descramble the data according to a decimated long code sequence which, as described with respect to the decoded long code sequences, is used to encode the data in 2 to scramble.

The descrambled or descrambled data are sent to the ent-permutators (DE-INT = de-interleaver). 116a - 116c delivered. The Ent-permutators 116a - 116c arrange the symbols in a new order (reorder) according to the selected de-permutation formats generated by the control processor 125 to be delivered. In an exemplary embodiment, the control processor (CONTROL PROCESSOR) provides 125 a signal indicating the size of the ent-permuter and the scheme of de-permuting for each of the ent-permuters (DE-INT) 116a - 116c , In the exemplary embodiment, the Entpermutiererschema is selected from a predetermined set of bit reverse Ent-permutation schemes.

The de-permuted symbols are then sent to symbol combiner (SYMBOL COMBINER) 118a - 118c which coherently combine the repeatedly transmitted or transmitted symbols. The combined symbols (soft decisions = soft decisions) are then sent to the variable ratio multiplexer (MUX) 120 which rearranges the data stream and sends the reassembled data stream to the decoder (DECODE). 122 supplies. The exemplary embodiment of the decoder 122 is a "maximum likelihood" decoder whose implementation is known in the art. In the exemplary embodiment, the decoder includes 122 a buffer (not shown) which waits until an entire frame of data is delivered before beginning the decoding process. The decoded frame is sent to the CRC check or check means (CRC-CHECK) 124 which determine whether the CRC bits correspond to the test and if so, they are delivered to the user or otherwise a cancellation is declared.

Having described the invention with reference to a preferred embodiment It is to be understood, however, that the embodiment in question is intended to be exemplary only, and that modifications and variations will be apparent to those skilled in the art without departing from the scope of the invention as defined in the appended claims.

Claims (38)

A transmitter for a multi-carrier CDMA message system for transmitting data at a data rate in a plurality of channels, each having a capacity that is less than the data rate, and the transmitter comprising: a controller (controller) ( 50 ) for determining the capacity of each of the plurality of channels and selecting a data rate for each channel depending on the determined capacity; a plurality of transmission subsystems; and a variable demultiplexer ( 56 ) in response to the control device ( 50 ) for demultiplexing the encoded data into a plurality of transmission subsystems at a demultiplex rate derived from the data rates selected for the channels by the control device ( 50 ), wherein the plurality of transmission subsystems to the control device ( 50 ) and each associated with a corresponding channel of the plurality of channels for scrambling the encoded data with codes unique to the channel for transmission or transmission in the channel. A transmitter according to claim 1, further comprising an encoder ( 54 ) is provided for generating the encoded data from data frames that have been input. A transmitter according to claim 1 or 2, wherein each of the transmitter or transmitter subsystems comprises a symbol repeat unit ( 58 ) for repeating the symbols for outputting the same at a rate corresponding to the rate selected for the channel by the control device (Fig. 50 ). A transmitter according to claim 3, wherein each transmission subsystem comprises a permutation unit ( 60 ) for rearranging the repeated symbols depending on the control device ( 50 ) particular permutation or interleaving format. A transmitter according to claim 4, further comprising a long code generator ( 82 ) is provided for generating a corresponding long code for each channel; and wherein in each transmission subsystem a scrambler ( 62 ) is provided for scrambling the reordered symbols using the corresponding code for the channel. Transmitter according to claim 5, wherein the long code generator ( 82 ) a decimator unit for each channel ( 84 ) for decimating a generated long code with a decimation rate determined by the control device ( 50 ) so as to generate corresponding long codes for each channel. A transmitter according to claim 6, further comprising variable coding units 66 are provided in each transmission subsystem for modeling the scrambled symbols from the scrambler ( 62 ). Transmitter according to Claim 7, in which the coding units ( 66 ) are arranged to model the scramble symbols with a corresponding Walsh code. A transmitter according to claim 7 or 8, further comprising a pseudo noise spreader ( 68 ) is provided in each channel for spreading the modeled symbols. A transmitter or transmitter according to any one of the preceding claims, further comprising: a switch ( 74 ); and a plurality of carrier modulators ( 76 ), the switch ( 74 ) on the control device ( 50 ) to switch the scrambled data on one of the plurality of transmit subsystems between the plurality of carrier modulators ( 76 ) for modulating the signals (different carriers at different times). A receiver for a multi-carrier CDMA message system, the receiver comprising: a receive circuit ( 102 ) for receiving signals simultaneously in a plurality of channels, each of the signals defining scrambled coded symbols which collectively collect data from a common source or a common origin; a control device ( 125 ) for determining a symbol rate for the signals in each channel; a plurality of receiving subsystems in response to the control device ( 125 ) and each associated with a corresponding channel of the plurality of channels for descrambling or descrambling ( 114 ) the coded symbols with codes unique to the channel to allow the data to be extracted therefrom; and a variable multiplexer ( 120 ) in response to the control device ( 125 ) for multiplexing the data from the plurality of receiving subsystems at a multiplex rate derived from the symbol rates determined for the channels by the control device ( 125 ) at an exit. A receiver according to claim 11, further comprising a decoder ( 122 ) is provided for decoding the coded data output by the multiplexer ( 120 ) in data frames. A receiver according to claim 11 or 12, further comprising a pseudo noise canceler ( 108 ) in each channel to despread the scrambled and coded symbols. A receiver according to claim 13, further comprising variable decoding units ( 110 ) are provided in each receiving subsystem for demodulating the despread symbols from the despreader ( 108 ). A receiver according to claim 14, wherein the decoding units ( 110 ) are arranged to demodulate the despread symbols with a corresponding Walsh code. The receiver of claim 15 further comprising a descrambler (in each receive subsystem). 114 ) is provided for descrambling the despread symbols using a corresponding long code for the channel. A receiver according to claim 16, wherein each receiving subsystem comprises a deinterleaving unit ( 116 ) for rearranging the repeated symbols depending on an interleaving format determined by the control device ( 125 ). A receiver according to claim 17, wherein each receive subsystem comprises a symbol combiner ( 118 ) for combining the symbols to output them to the multiplexer ( 120 ) at a rate corresponding to the rate determined for the channel by the control device ( 125 ). A receiver according to any one of claims 11 to 18, further comprising: a switch ( 104 ); and a plurality of carrier demodulators ( 106 ), the switch ( 104 ) on the control device ( 125 ) is responsive to the received signals between the plurality of carrier demodulators ( 106 ) and to demodulate the signals in different Empfangssubsysteme at different times. A method of transmitting or transmitting data in a multicarrier CDMA message system at a data rate in a plurality of channels, each having a capacity less than the data rate, the method comprising: determining ( 50 ) the capacity of each of the plurality of channels and selecting a data rate for each channel depending on the determined capacity; Demultiplexing ( 56 ) of the coded data into the plurality of channels at a demultiplex rate derived from the data rates selected for the channels by the control device ( 50 ); and scrambling the encoded data with codes unique to the channel for transmission in the channel. The method of claim 20, further comprising an encoder ( 54 ) is provided for generating coded data from input data frames. The method of claim 20 or 21, further comprising: repeating ( 58 ) of the symbols for each channel to output the same at a rate corresponding to the rate selected for the channel. The method of claim 22, further comprising: reordering (FIG. 60 ) of repeated symbols depending on a particular interleaving format. The method of claim 23, further comprising: generating ( 82 ) of a corresponding long code for each channel; and scrambling ( 62 ) of the reordered symbols in each transmit subsystem using the corresponding code for the channel. The method of claim 24, wherein the long code for each channel is decimated ( 84 ) of a second long code is generated at a predetermined decimation rate for each channel ( 82 ). The method of claim 25, further comprising modulating ( 66 ) of the scrambled symbols is provided with a code. The method of claim 26, wherein the scrambled symbols are modulated with a corresponding Walsh code ( 66 ) are. The method of claim 26 or 27, further comprising spreading ( 68 ) of the modulated symbols is provided with pseudo noises. The method of any one of claims 20 to 28, further comprising modulating ( 76 ) of the scrambled data is provided on different carriers at different times. A method of receiving data in a multi-carrier CDMA message system, the method comprising: receiving ( 102 ) of signals simultaneously in a plurality of channels, each of the signals defining scrambled coded symbols which together represent the data from a common origin; Determine ( 125 ) a symbol rate for the signals in each channel; Descramble ( 114 ) the coded symbols in each channel with codes unique to the channel to allow extraction of the data therefrom; and multiplexing ( 120 ) of the descrambled data from the plurality of channels at a multiplex rate derived from the symbol rates determined for the channels. The method of claim 30, further comprising: decoding ( 122 ) of the multiplexed coded data in data frames. The method of claim 30 or 31, further comprising despreading ( 108 ) of the encrypted or scrambled coded symbols is provided using a pseudo noise code. The method of claim 32, further comprising demodulating ( 110 ) of the despread symbols is provided by variable decoding. The method of claim 33, wherein the despread symbols are demodulated with a corresponding Walsh code ( 110 ) become. The method of claim 34, further comprising descrambling ( 114 ) of the despread symbols in each channel using a corresponding long code for the channel. The method of claim 35, further comprising rearranging ( 116 ) of the repeated symbols is provided depending on a particular deinterleaving format. The method of claim 36, further comprising: combining ( 118 ) of symbols in a channel before multiplexing ( 120 ) thereof at a rate corresponding to the rate determined for the channel. The method of any one of claims 30 to 37, further comprising: demodulating ( 106 ) of the signals in different channels at different times.